Not much going on at lunch.

We went last June at 12pm and saw none of the famous antics, pony rides, etc... Our waitress was fun, but that's it. It's not at all loud. I spoke with a Dining CM that said Breakfast and Dinner is when they really go all out. I never would have thought for breakfast, I would have expected breakfast to be tame and lunch to be fun. The CM said breakfast is a real hoot!
If your going for the food, lunch is fine. If you want the whole dining experience, then go for breakfast or dinner.